View source for Physics:Condensation

{{Short description|Condensation is the change of state of matter from a gas phase into a liquid phase.}}
[[File:Cloud over A340 wing.JPG|thumb|right|Condensation forming in the low pressure zone above the wing of an aircraft due to [[Physics:Adiabatic process|adiabatic]] expansion]]

'''Condensation''' is    the change of the [[Physics:State of matter|state of matter]] from the [[Physics:Gas|gas phase]] into the [[Physics:Liquid|liquid phase]], and is the reverse of [[Physics:Vaporization|vaporization]]. The word most often refers to the [[Physics:Water cycle|water cycle]].<ref name=Gold>{{GoldBookRef|title=condensation ''in atmospheric chemistry''|file=C01235}}</ref> It can also be defined as the change in the state of water vapor to liquid water when in contact with a liquid or solid surface or [[Physics:Cloud condensation nuclei|cloud condensation nuclei]] within the atmosphere. When the transition happens from the gaseous phase into the solid phase directly, the change is called [[Physics:Deposition (phase transition)|deposition]].

==Initiation==
Condensation is initiated by the formation of atomic/molecular clusters of that species within its gaseous volume—like rain drop or snow flake formation within [[Earth:Cloud|cloud]]s—or at the contact between such gaseous phase and a liquid or solid surface. In clouds, this can be catalyzed by [[Biology:Bacterial ice-nucleation proteins|water-nucleating proteins]], produced by atmospheric microbes, which are capable of binding gaseous or liquid water molecules.
<ref>{{cite news |last=Schiermeier |first=Quirin |url=https://www.nature.com/news/2008/080228/full/news.2008.632.html |title='Rain-making' bacteria found around the world |work=Nature |date=2008-02-28 |access-date=2018-06-21 }}</ref>

==Reversibility scenarios==
A few distinct reversibility scenarios emerge here with respect to the nature of the surface.
* absorption into the surface of a liquid (either of the same substance or one of its solvents)—is reversible as [[Physics:Evaporation|evaporation]].<ref name="Gold"/>
* [[Chemistry:Adsorption|adsorption]] (as dew droplets) onto solid surface at pressures and temperatures higher than the species' [[Chemistry:Triple point|triple point]]—also reversible as evaporation.
* adsorption onto solid surface (as supplemental layers of solid) at pressures and temperatures lower than the species' [[Chemistry:Triple point|triple point]]—is reversible as sublimation.

==Most common scenarios==
Condensation commonly occurs when a [[Chemistry:Vapor|vapor]] is cooled and/or compressed to its [[Physics:Dew point|saturation limit]] when the molecular density in the gas phase reaches its maximal threshold. Vapor cooling and compressing equipment that collects condensed liquids is called a [[Physics:Condenser (heat transfer)|"condenser"]].
[[File:Condensation on outside of windows.png|thumb|Condensation on the outside of a window, due to it being in front of the sea which regularly produces moist [[Earth:Sea spray|sea spray]].]]

== Measurement ==
Psychrometry measures the rates of condensation through evaporation into the air moisture at various atmospheric pressures and temperatures. Water is the product of its vapor condensation—condensation is the process of such phase conversion.

== Applications of condensation ==
[[File:Effect similar to contrails created in a cloud chambers.jpg|thumb|In cloud chambers a liquid (sometimes water, but usually isopropanol) condenses upon contact with a particle of radiation thus producing an effect similar to contrails]]
Condensation is a crucial component of [[Distillation|distillation]], an important laboratory and industrial chemistry application.

Because condensation is a naturally occurring phenomenon, it can often be used to generate water in large quantities for human use. Many structures are made solely for the purpose of collecting water from condensation, such as [[Earth:Air well (condenser)|air wells]] and fog fences. Such systems can often be used to retain soil moisture in areas where active [[Earth:Desertification|desertification]] is occurring—so much so that some organizations educate people living in affected areas about water condensers to help them deal effectively with the situation.<ref>[http://www.fogquest.org/ FogQuest - Fog Collection / Water Harvesting Projects - Welcome<!-- Bot generated title -->] {{webarchive|url=https://web.archive.org/web/20090223071843/http://www.fogquest.org/ |date=2009-02-23 }}</ref>

It is also a crucial process in forming particle tracks in a [[Physics:Cloud chamber|cloud chamber]].  In this case, ions produced by an incident particle act as nucleation centers for the condensation of the vapor producing the visible "cloud" trails.

Commercial applications of condensation, by consumers as well as industry, include power generation, water desalination,<ref name=WarsingerEntropy>{{Cite journal|last1=Warsinger|first1=David M.|last2=Mistry|first2= Karan H.|last3=Nayar|first3=Kishor G.|last4=Chung|first4=Hyung Won|last5=Lienhard V.|first5=John H.|title=Entropy Generation of Desalination Powered by Variable Temperature Waste Heat|journal=Entropy|volume=17|issue=11|pages=7530–7566|doi=10.3390/e17117530|date=2015|bibcode=2015Entrp..17.7530W|doi-access=free}}</ref> thermal management,<ref>White, F.M. ‘Heat and Mass Transfer’ © 1988 Addison-Wesley Publishing Co. pp. 602–604</ref> refrigeration,<ref>Q&A: Microchannel air-cooled condenser; Heatcraft Worldwide Refrigeration; April 2011; {{cite web |url=http://www.heatcraftrpd.com/landing/2011/air-cooled-condenser/res/pdfs/H-ACCMCX-QA.pdf |title=Archived copy |access-date=2013-02-20 |url-status=live |archive-url=https://web.archive.org/web/20120417093034/http://www.heatcraftrpd.com/landing/2011/air-cooled-condenser/res/pdfs/H-ACCMCX-QA.pdf |archive-date=2012-04-17 }}</ref> and air conditioning.<ref name="Enright">{{cite journal|last1=Enright|first1=Ryan|title=Dropwise Condensation on Micro- and Nanostructured Surfaces|journal=Nanoscale and Microscale Thermophysical Engineering|date=23 Jul 2014|volume=18|issue=3|pages=223–250|doi=10.1080/15567265.2013.862889|bibcode=2014NMTE...18..223E|hdl=1721.1/85005|s2cid=97855214|url=https://dspace.mit.edu/bitstream/1721.1/85005/1/Dropwise%20Condensation%20on%20Micro-%20and%20Nanostructured%20Surfaces.pdf |archive-url=https://web.archive.org/web/20190923125031/https://dspace.mit.edu/bitstream/1721.1/85005/1/Dropwise%2520Condensation%2520on%2520Micro-%2520and%2520Nanostructured%2520Surfaces.pdf |archive-date=2019-09-23 |url-status=live|hdl-access=free}}</ref>

== Biological adaptation ==
Numerous living beings use water made accessible by condensation. A few examples of these are the {{wipe|Australia}}n [[Biology:Thorny devil|thorny devil]], the [[Biology:Darkling beetle|darkling beetle]]s of the Namibian coast, and the [[Biology:Sequoia sempervirens|coast redwoods]] of the West Coast of the United States.

==Condensation in building construction==
[[Image:Window in Ireland.jpg|right|thumb|Condensation on a window during a rain shower.]]
Condensation in building construction is an unwanted [[Philosophy:Phenomenon|phenomenon]] as it may cause dampness, [[Biology:Mold health issues|mold health issues]], [[Biology:Wood|wood]] [[Biology:Dry rot|rot]], [[Chemistry:Corrosion|corrosion]], weakening of mortar and masonry walls, and energy penalties due to increased [[Physics:Heat transfer|heat transfer]]. To alleviate these issues, the indoor air humidity needs to be lowered, or air ventilation in the building needs to be improved. This can be done in a number of ways, for example opening windows, turning on extractor fans, using dehumidifiers, drying clothes outside and covering pots and pans whilst cooking. Air conditioning or ventilation systems can be installed that help remove moisture from the air, and move air throughout a building.<ref name=PropertyHive>{{cite web |url=http://www.wisepropertycare.com/condensation |title=Condensation |publisher=Property Hive |url-status=dead |archive-url=https://web.archive.org/web/20131213114908/http://propertyhive.org/condensation/ |archive-date=2013-12-13}}</ref> The amount of water vapor that can be stored in the air can be increased simply by increasing the temperature.<ref name=PropertyHive /> However, this can be a double edged sword as most condensation in the home occurs when warm, moisture heavy air comes into contact with a cool surface. As the air is cooled, it can no longer hold as much water vapor. This leads to deposition of water on the cool surface. This is very apparent when central heating is used in combination with single glazed windows in winter.

Interstructure condensation may be caused by [[Physics:Thermal bridge|thermal bridge]]s, insufficient or lacking insulation, [[Engineering:Damp proofing|damp proofing]] or [[Physics:Insulated glazing|insulated glazing]].<ref>{{cite web |url=http://www.diydata.com/problem/condensation/condensation.php |title=Condensation around the house - what causes condensation |website=diydata.com |url-status=live |archive-url=https://web.archive.org/web/20080113064649/http://www.diydata.com/problem/condensation/condensation.php |archive-date=2008-01-13 }}</ref>

==Table==
{{Table_of_phase_transitions}}

==See also==
{{Div col|small=yes}}
* [[Earth:Air well (condenser)|Air well (condenser)]]
* [[Physics:Bose–Einstein condensate|Bose–Einstein condensate]]
* [[Physics:Cloud physics|Cloud physics]]
* [[Physics:Condenser (heat transfer)|Condenser (heat transfer)]]
* [[Biology:DNA condensation|DNA condensation]]
* [[Physics:Dropwise condensation|Dropwise condensation]]
* [[Biology:Groasis Waterboxx|Groasis Waterboxx]]
* [[Physics:Kelvin equation|Kelvin equation]]
* [[Physics:Liquefaction of gases|Liquefaction of gases]]
* [[Phase diagram]]
* [[Physics:Phase transition|Phase transition]]
* [[Physics:Retrograde condensation|Retrograde condensation]]
* [[Physics:Surface condenser|Surface condenser]]
{{Div col end}}

==References==
{{Reflist}}

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{{States of matter}}

[[Category:Phase transitions]]

{{Sourceattribution|Condensation}}